Multiplexed Rectilinear Ion Trap Mass Spectrometer for High-Throughput Analysis

Abstract

A multichannel mass spectrometer based on the rectilinear ion trap (RIT) analyzer was designed and constructed for simultaneous high-throughput analysis of multiple samples. The instrument features four parallel ion source/mass analyzer/detector channels assembled in a single vacuum chamber and operated using a common set of control electronics, including a single rf amplifier and transformer coil. This multiplexed RIT mass spectrometer employs an array of four millimeter-sized ion traps (x(o) = 5.0 mm and y(o) = 4.0 mm, where x(o) and y(o) are the half-distances in the x and y dimensions, respectively). Mass spectra are acquired from four different samples simultaneously. The available mass/charge range is m/z 15-510 with excellent linearity of the mass calibration (R2 = 0.999 999). The peak width is less than 0.3 mass/charge units at m/z 146, corresponding to a resolution of approximately 500. Simultaneous MS/MS of ions due to four compounds (3-fluoroanisole, 4-fluoroanisole, 2-fluorobenzyl alcohol, 2,6-dimethylcyclohexanone) with the same nominal molecular radical cation but distinctive fragmentation patterns was demonstrated. Isolation and fragmentation efficiencies were approximately 25 and approximately 75%, respectively, measured in the typical case of the molecular radical cation of acetophenone. Preacquisition differential data were obtained by real-time subtraction of the ion signals from two channels of the multiplexed mass spectrometer. The differential experiment presented offers proof of principle of comparative mass spectra in high-throughput screening applications while reducing data storage requirements.

Circular arrays of polymer-based miniature rectilinear ion traps

“…For example, a multi-channel rectilinear ion trap (RIT) system consisting of four physically separate RITs was operated using a single sub-divided vacuum manifold; the individual channels shared electrical systems including a common high voltage RF source. 7 The combination of mass analyzer miniaturization with multiplexing has the potential to realize a significant increase in ion trap sensitivity, as recognized by Kirchner. 8 In this vein, parallel arrays of small CITs have been built in the form of microfabricated chips.…”

Advantageous Uses of Mass Spectrometry for the Quantification of Proteins

“…Even under very fast analytical conditions, such as MALDI-Tof analysis, each sample will require a few seconds to process. Future developments in multiplexed mass spectrometric detectors may help to address this limitation [43]. …”

Optimization and simulation of MEMS rectilinear ion trap

“…5 Furthermore, by virtue of its characteristics, such as more convenient process and larger ion capacity, the rectilinear ion trap has become the current research focus in the research field of ion traps. 6,7 Portable mass spectrometers with rectilinear ion traps have been developed by several research institutions as model machines in laboratories or as commodities. Among them, the most famous one is the MINI series portable mass spectrometer reported by Cooks and Ouyang at Purdue University.…”